title: The influence of polymorphisms of VKORC1 and CYP2C9 on major gastrointestinal bleeding risk in anticoagulated patients.
abstract: The VKORC1 c.-1639G>A and CYP2C9 c.430C>T and c.1075A>C polymorphisms have been associated with increased sensitivity to oral anticoagulants. However, their role in gastrointestinal bleeding is unknown. We studied the risk of gastrointestinal bleeding associated with these polymorphisms, and how this risk was influenced by the anticoagulant dose and the use of common drugs. Eighty-nine patients with gastrointestinal bleeding during acenocoumarol therapy and 177 patients free of bleeding during acenocoumarol therapy were studied. None of the three polymorphisms constituted a serious gastrointestinal bleeding risk factor. However, patients bearing at least one of these polymorphisms were at high risk, when they simultaneously met one of the following conditions: a weekly dose of acenocoumarol higher than 15 mg [adjusted Odds Ratio (OR) (95% confidence interval (CI) = 4.19 (1.59-11.04)]; amiodarone use [adjusted OR (95% CI) = 9.97 (1.75-56.89)]; or aspirin use [adjusted OR (95% CI) = 8.97 (1.66-48.34)]. The consumption of statins was associated with a lower risk of gastrointestinal bleeding [adjusted OR = 0.50 (0.26-0.99)]. The risk of gastrointestinal bleeding during acenocoumarol therapy in carriers of any of the studied polymorphisms is severely increased with exposure to weekly doses of acenocoumarol higher than 15 mg or the use of amiodarone or aspirin.
authors.affiliation: Haematology Department and the Division of Cardiovascular Sciences, Laboratory of Thrombosis and Haemostasis, Applied Medical Research Centre and Clinica Universitaria/School of Medicine, University of Navarra, Pamplona, Navarra, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Montes
authors.forename: Oscar
authors.initials: O
authors.lastname: Nantes
authors.forename: Alvaro
authors.initials: A
authors.lastname: Alonso
authors.forename: José M
authors.initials: JM
authors.lastname: Zozaya
authors.forename: José
authors.initials: J
authors.lastname: Hermida
mesh_terms: D000074:Acenocoumarol / Q000009:adverse effects* / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D000638:Amiodarone / Q000009:adverse effects / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects / Q000627:therapeutic use; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use; D016022:Case-Control Studies; D065729:Cytochrome P-450 CYP2C9; D004334:Drug Administration Schedule; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D019934:International Normalized Ratio; D008297:Male; D006899:Mixed Function Oxygenases / Q000235:genetics*; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012306:Risk; D064417:Vitamin K Epoxide Reductases
chemical_list: D000889:Anti-Arrhythmia Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000925:Anticoagulants; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D006899:Mixed Function Oxygenases; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases; C578523:VKORC1 protein, human; D064417:Vitamin K Epoxide Reductases; D000074:Acenocoumarol; D000638:Amiodarone; D001241:Aspirin